Magnetic and vacuum cleaning device for printer

ABSTRACT

Means are provided to remove particles from unwanted portions of a recorded surface which has been powdered for printing. The means include a slotted tube which is selectively magnetizable to form a weak magnetic field and attract the unwanted magnetic particles. The attract particles are then removed by the air pressure and exhaust means.

United States Patent 51 3, 59,526

Staller [4 1 May 2, 1972 541 MAGNETIC AND VACUUM CLEANING 2,318,570 5/1943 Carlton ..10l/DIG. 13

DEVICE FOR PRINTER 2,920,987 1/1960 Landry et a].

2,576,047 11/1951 Schaffert 1 lnvemofi Karel Stall", Rutherford 3,052,564 9/1962 Kulesza ..101/D1G. 13

73 Assi nee: International Tele hone and Tel h 1 g Cowman, Nutle; NJ. egmp Primary Examiner-Robert E. Pulfrey Assistant Examiner-R. E. Suter [22] Med: Dec. 8, 1969 AnorneyC. Cornell Remsen, .lr., Walter J. Baum, Paul W. l-lemminger, Percy P. Lantzy, Phillip M. Bolton, Isidore Togut [211 App]' 882983 and Charles L. Johnson, Jr.

[52] U.S. Cl ..101/425, 15/15 [57] ABSTRACT [51] Int. Cl. ..B4ll' 35/02 Means are provlded to remove part1cles from unwanted por- [58] F eld ofSearch ..101/425,D1G. 13, 15/].5 {ions of a recorded Surface which has been powdered for 56] References Cited printing. The means include a slotted tube which is selectively magnetizable to form a weak magnetic field and attract the UNITED STATES PATENTS unwanted magnetic particles. The attract particles are then removed by the air pressure and exhaust means. 2,832,977 5/1958 Walkup et al ..101/425 2,582,939 1/1952 Frederick ..15/1 .5 1 Claims, 2 Drawing Figures Patented May 2, 1972 llllllllllllllllllln INVENTOR KAREZ 1/.STAlLE/Q BY M ATTORNEY m Vii MAGNETIC AND VACUUM CLEANING DEVICE FOR PRINTER BACKGROUND OF THE INVENTION In general this invention relates to a displaced particle removing apparatus, and more particularly to a means of improving the quality of printing by providing a displaced particle removing apparatus for removing excess and unwanted particles.

In order to improve the quality of printing, for instance, on printers, using magnetic powders which have been attracted to magnetized portions of a drum or other recording medium, means must be provided for removing particles which do not directly adhere to the magnetized portions of the recording medium. It happens that some particles rest in the field between the magnetic characters formed by selective recording, and the particles which rest between the fields are held by static electricity or by adhesion in this unwanted position. In exsiting printing arrangements, these unwanted characters are removed by blowing air against the surface of the recording medium. This method has a serious drawback that the particles are shifted to the closest magnetized portion of the recording surface and adding to the particles already at that particular magnetized portion. This as can be readily understood emphasizes certain portions of the printout in comparison to the complete printing copy. This results in a very uneven and poor quality of printout. This becomes a very serious problem in high speed printers which then produce uneven copies, or copies with black particles pressed onto the copy at random points.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a means to improve quality of printout on printers by using a displaced particle removing apparatus.

It is another object of this invention to provide means to remove displaced particles from unwanted portions of a recorded surface which has been powdered for printing.

According to the broader aspects of the invention, there is provided a means to remove displaced particles which are retained on unwanted portions of a magnetic surface which has been powdered for printing, the means including a slotted tube which selectively forms a weak magnetic field to attract the displaced magnetic particles from the unwanted portions of the powdered magnetic recording surface, the attracted particles then being removed by an air pressure and exhausting means.

BRIEF DESCRIPTION OF THE DRAWINGS The objects of this invention will more easily be understood if the description is read in connection with the following drawings in which:

FIG. 1 illustrates a magnetic printing arrangement utilizing the displaced magnetic particle removing apparatus according to the invention; and

FIG. 2 illustrates a cross sectional view of the displaced magnetic particle removing apparatus of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is illustrated a magnetic printing arrangement utilizing, for purposes of description of the displaced particle removing apparatus, a printing drum l1 rotating in the direction of the arrow 12. Positioned about the circumference of the drum is a printout station 13, an erasing and cleaning station 14, a recording station 15, a powdering station 16, and the displaced magnetic particle removing apparatus 17. The drum has a magnetizable circumference 18 which is magnetized at the recording station at the predetermined locations 19. As the drum passes under the powdering station 16, powder particles 20 are attracted and retained at the selected magnetized portions 20 of the drum surface 18. In addition, some particles 20 are held by static electricity or by adhesion in unwanted positions 21.

Since the particles in positions 21 are lightly held in position only by static electricity or mechanical adhesion, they can be removed at the removing apparatus 17 prior to printing. As previouslymentioned prior arrangements forced air directly on these particles so that they would be shifted towards the magnetic portions of the printing surface, thereby creating excess particles at some magnetized points. However, with the arrangement of the displaced magnetic particles removing apparatus 17 these particles are removed rather than shifted to the closest magnetic portion 19 of the drum surface 18.

The apparatus includes a steel tube 22 which is slotted at 23. Within the tube is a wire conductor 24 which is surrounded by an inner plastic support 25 forming a portion of the inner tube so that an exhaust cavity 26 remains within the tube and adjacent the slot gap portion 23. Mounting the slotted steel tube is an outer mounting means 27 which could be also a plastic tube which provides an air pressure cavity 28 and a corresponding gap 29 larger than the gap in the steel tube and opposite the drum surface. As the drum rotates past the gap 29 of the support means 27, the particles 20 at positions 21 are attracted to the steel tube when the wire 24 within the tube passes a high frequency current. The lightly attached particles are attracted to the rim portion 23 of the tube and withdrawn into the exhaust gap 26 as further described.

The arrangement of the displaced magnetic particle removing apparatus 17 is more clearly understood if further reference is made to FIG. 2, which is a cross-sectional view of the apparatus as shown in FIG. 1. Illustrated generally is the outline of the printing drum 11 together with the apparatus 17 in the axial direction of the drum. The steel tube 22 has a longitudinal air gap 23 longer than the drum axial length. Mounted within the core of the tube, by means of an inner nonmagnetic support 25 is the wire 24 coupled to a high frequency current source 30. The outer support mounting means 27 contains the corresponding gap 29 and includes another cavity 28 which is coupled to a blower means 31 for forcing air into the cavity 28. An exhaust means 32 is provided and coupled by the coupling extension 33 to the mounting means 27. The air introduced from the blower means 31 passes through the air pressure gap 28, picks up the magnetic particles which have adhered to the edges 34 of the longitudinal gap 23 and removes them via the exhaust tube means 33.

This arrangement uses the air exhaust only to remove the displaced particles retained on edges of the slotted steel tube without the air flow effecting the particles which are retained on the surface of the drum by the magnetized portions of the drum.

Therefore, the invention described removes the particles in a direction perpendicular to the surface of the drum. The insulated wire within the core of the steel tube carries a high frequency current. The steel tube has a longitudinal gap so that the unwanted particles are attracted in the gap and are transported by air flow out of the tube. For this purpose there has been provided air which is introduced into the plastic mounting support and exhaust means are included to remove the particles resting on the edges of the longitudinal gap of the steel tube. The support and mounting means has a longitudinal slot which is spaced from the drum, so that the air introduced into the gap does not influence the position of the particles on the drum.

Although I have described the invention in connection with specific apparatus, it should be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

I claim:

1. In a magnetic printing arrangement a displaced magnetic particle removing apparatus comprising:

a steel tube slotted to form a longitudinal gap, said gap having a length at least equal to the width of a powdered magnetic recording surface in said printing arrangement;

means for conducting a high frequency current through the interior of said tube, including a wire conductor running the axial length of said tube and comprising only a portion with its gap adjacent said recording surface; and

means coupled to said mounting means for introducing air into said cavity, and means coupled to said slotted tube for exhausting through said exhaust cavity said attracted magnetic particles. 

1. In a magnetic printing arrangement a displaced magnetic particle removing apparatus comprising: a steel tube slotted to form a longitudinal gap, said gap having a length at least equal to the width of a powdered magnetic recording surface in said printing arrangement; means for conducting a high frequency current through the interior of said tube, including a wire conductor running the axial length of said tube and comprising only a portion of the interior of said tube, and the remaining portion forming an exhaust cavity; means for mounting said slotted tube and providing a cavity through which displaced particles are attracted to the edge of said slotted tube, said means including a non-metallic tubular member having a gap in its surface larger than said longitudinal gap, and said member positioned with its gap adjacent said recording surface; and means coupled to said mounting means for introducing air into said cavity, and means coupled to said slotted tube for exhausting through said exhaust cavity said attracted magnetic particles. 